Figure 15 lm386 internal circuit and 8pin dip pin assignments. Be base readymade circuit for side sound work and the communication. The circuit shown in figure 1 is a very simple audio power amplifier. This audio amplifier circuit is useful in classrooms to reduce the strain of lecturing,if the surrounding environment is noisy. For stereo application, just build the identical circuit. This is probably the worlds most popular audio power amplifier integrated circuit ever made. This article discusses an overview of the ic lm380 audio amplifier and its applications. The lm380 is a low power audio amplifier used especially for power audio amplification purposes. Simple mic audio amplifier can amplify sound that is given from microphone. This be mini size power amplifier 2 watt otl that use ic lm380. Video demonstrates the assembly of an lm380 audio amplifier circuit. The second inverting amplifier mounted on the same audio signal line and connected at the input.
This is the very simple circuit of mini audio amplifier single channel mono using low cost ic lm380. The simplicity of this circuit is made possible by the lm380s minimal requirements for external components, since it is already internally equipped with the necessary biasing, compensation, and gain circuits. Lm380 datasheet, lm380 pdf, lm380 data sheet, lm380 manual, lm380 pdf, lm380, datenblatt, electronics lm380, alldatasheet, free, datasheet, datasheets, data sheet. In order to hold system cost to a low quiescent power drain. But after prototyping with this audio amp i dont think ill ever go back to the lm386. Audio power amplifier circuit diagrams circuit schematics. With this arrangement we get an output voltage swing which is twice that of a single lm380 amplifier. The lm380 is an older but nonetheless still usable audio amplifier. Uses include simple phonograph amplifiers, intercoms, line drivers, teaching machine outputs, alarms, ultrasonic drivers, tv sound systems, amfm radio, small servo drivers, power converters, etc. Lm380 audio power amplifier power amplifiers, audio. Ive read the lm380 amplifier data sheet and application notes, and they show a power supply ripple rejection number thats based on the size of the bypass capacitor. The series of three miniamplifier transistors can be used for loud speaker 8 ohm load. The circuit is using lm380n version which is a 14 pin dip package ic with good features like it can be operated on a wide range of voltage from 10v to 22v, drains low quiescent power, low distortion etc.
In order to hold system cost to a minimum, gain is internally fixed at 34 db. While it looks very similar to the lm386 circuit shown above, note that the pin numbers are different. Ive shown the lm380 with the same component values as the lm386, and performance will be similar, but you can get higher power. If a certain application requires more power than what is provided by a single lm380 amplifier, then 2 lm380 chips can be used in the bridge configuration. Audio power amplifier is an amplifier which produces amplification of power between the input and output. This circuit can also be used in many applications like portable music players, intercoms, radio amplifiers, tv sound systems, ultrasonic drivers etc. This is an old chip that has been a popular choice for lowpower audio applications for many years. The circuit of watt audio power amplifier using can you see in the picture below mini 3 transistor amplifier is a simple amplifier with power drawn by 3 transitor. The output automatically selfcenters to onehalf the supply voltage. The output is short circuit proof with internal thermal limiting. Circuit assembly tutorials lm380 audio amplifier youtube. Note that all these links are external and we cannot provide support on the circuits or offer any guarantees to their accuracy.
Circuit diagram for a simple lm380based audio power amplifier. A unique input stage allows inputs to be ground referenced or ac coupled as required. It features an internally fixed gain of 50 34 db and an output which automatically centers itself at onehalf of the supply voltage. Integrated circuit audio amplifiers by mike martell n1hfx. Some circuits would be illegal to operate in most countries and others are dangerous to construct and should not be attempted by the inexperienced. I was a little intimidated by this ic the first time i looked at the datasheet because of all the ground connections. Input stage allows the input to be ground referenced or ac coupled. I used the inductor symbol to represent the speaker.
Circuit description figure 1shows a simplified circuit schematic of the lm380. Output is short circuit proof with internal thermal limiting. If you use the external circuit a, replace the rx with a jumper wire in the pcb. In order to hold system cost to a minimum, a gain is internally fixed at 34 db. The simplicity of this circuit is made possible by the lm380s minimal requirements for external components, since it is already internally. Lm380n8 audio amplifier circuit ic is an another 8 pin dip version of lm380n audio amplifier ic which is available in 14 pin dip package. Testing my finished stereo amplifier that i build using two lm380 ics. The power output is around 550 mw at 16 ohm speaker impedance. Output is automatically self centring to one half of the supply voltage. The circuit is using lm380n version which is a 14 pin dip package ic with good features like it can be operated on a wide range. If anyone knows where i can find a ltspice model for a lm380 please share.
Nsc, alldatasheet, datasheet, datasheet search site for electronic components and semiconductors, integrated circuits, diodes, triacs, and other semiconductors. Each channel outputs 2 watts rms giving a total output power of 4 watts max. The lm380 2 watt audio amplifier circuit shown here is an easy to build circuit using only few external parts and able deliver 2w to 2. Hello all, a few years back, i made a stereo amplifier, using a couple of lm380 ics. There are many other audio amp ics on the market lm380 and lm383 are similar but higherpower amps from national, but the lm386 is sufficient for our purposes. Lm380 audio power amplifier electronic projects circuits. The c6 can choose get many the value since 47uf to at 470uf which. If you use the external circuit c, solder the additional resistor and capacitor to the pcb points labeled rt and cy. Additionally, this ic offers high ip impedance, voltage gain is fixed, less power drain, etc.
Lm380 audio power amplifier december 1994 lm380 audio power amplifier general description the lm380 is a power audio amplifier for consumer application. Audio power amplifier, lm380 datasheet, lm380 circuit, lm380 data sheet. A specific input signal allows ground reference signal and the out signal maintains its level to the half of the applied input voltage. The ic comes in 8pin and 14pin pdip package and has a wide operating range hence it is highly easy to use. The circuit that i used was taken from an old textbook at my high school. This lm386 audio amplifier circuit can be used as small mic and loudspeaker system for a small space like a room. Lm380 audio power amplifier bridge stereo elec circuit.
Thirtyday moneyback guarantee and free product support. Whats the use of the bypass capacitor on the lm380 amplifier. While it is possible to build good audio amplifiers from discrete transistors, they are no match for the many audio amp ics available to us. The internal design of this ic can be fixed by designers like 34db. I fabricated two separate mono amplifiers on their own pcbs and then mounted them in a case. It uses the power amplifier ic lm380 that gives 2 watts output which is. Lm380 power audio amplifier circuit diagram circuit. This paper describes the circuit operation of the lm380, its power handling capability, methods of volume and tone control, distortion, and various application circuits such as a bridge amplifier, a power supply splitter, and a high input impedance audio amplifier. The lm380 ic is one kind of audio amplifier mainly used for power audio amplification. This audio frequency amplifier is ideal for small battery powered devices. Classical audio power amplifier with it and ot transformer electronic circuit power amplifier ocl 50 watt is a power amplifier that is now very popular and widely used for audio in homes.
Lm380 audio power amplifier national does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and national reserves the right at any time without notice to change said circuitry and specifications. Practical power amplifier stages and block diagram. In order to hold system costs to a minimum, the gain is internally fixed at 34 db. This means the current used by the loads cannot be driven straight through the generalpurpose amplifiers output. The main component of this circuit is the lm380 audio amplifier. Other than that, theres no actual mention of what this pin does or what the requirements are. Lm380 1features description wide supply voltage range. The lm380 is a power audio amplifier intended for consumer applications. Power audio amplifier ic lm 380 features, functional. New audio power amplifier for your electronics projects. I tend to prefer the sound that can be produced from an. It includes the very popular lm380 audio power amplifier 8pin ic rated at 2. The simplicity of this circuit is made possible by the lm380 s minimal requirements for external components, since it is already internally. The output automatically selfcentersto onehalfthe supply voltage.
See circuit diagram, components, and pcb layout design here. This ic includes a copper lead frame and features of this ic includes the range of supply is wide, less distortion. Power audio amplifier ic lm380 small signal amplifier are essentially voltage amplifier that supply their loads with larger amplifier signal voltage. A unique input stage allows inputs to be ground referenced. This is the lm380 audio power amplifier kit with pcb. Circuit diagram for a simple lm380 based audio power amplifier. Both the ics are able to deliver output power around 2w to 2. There are also a few designs that use trimmer potentiometers into the bypass pin. Theoretically every audio amplifier produces some amount of power amplification, but in practical scenario every audio amplifier cannot be called a power amplifier. A unique input stage allows ground referenced input signals. In a previous article i discussed building audio amplifiers using discrete transistors. I breadboarded the audio amplifier in the circuit below.
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